Various technologies may allow a user to experience a mix of real and virtual reality. For example, some display devices, such as various head mounted display (HMD) devices, may comprise a see-through display that allows superposition of virtual objects over a real-world environment. The virtual objects may appear integrated with the real-world environment when viewed by a wearer of the HMD device through the see-through display. Such a relationship between the virtual objects and the real-world environment may be referred to as augmented reality.